arm64: dts: qcom: sm8550: Separate out X3 idle state

The X3 core has different entry/exit/residency time requirements than
the big cluster. Denote them to stop confusing the scheduler.

Fixes: ffc50b2d ("arm64: dts: qcom: Add base SM8550 dtsi")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20231218-topic-8550_fixes-v1-11-ce1272d77540@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm64/boot/dts/qcom/sm8550.dtsi

@@ -300,6 +300,16 @@ BIG_CPU_SLEEP_0: cpu-sleep-1-0 {
 				min-residency-us = <4791>;
 				local-timer-stop;
 			};
+
+			PRIME_CPU_SLEEP_0: cpu-sleep-2-0 {
+				compatible = "arm,idle-state";
+				idle-state-name = "goldplus-rail-power-collapse";
+				arm,psci-suspend-param = <0x40000004>;
+				entry-latency-us = <500>;
+				exit-latency-us = <1350>;
+				min-residency-us = <7480>;
+				local-timer-stop;
+			};
 		};
 
 		domain-idle-states {
@@ -401,7 +411,7 @@ CPU_PD6: power-domain-cpu6 {
 		CPU_PD7: power-domain-cpu7 {
 			#power-domain-cells = <0>;
 			power-domains = <&CLUSTER_PD>;
-			domain-idle-states = <&BIG_CPU_SLEEP_0>;
+			domain-idle-states = <&PRIME_CPU_SLEEP_0>;
 		};
 
 		CLUSTER_PD: power-domain-cluster {